Kent and Wynter vie for starting place.
In Tuesday's win at Sheffield United, the central defender received a red card and has to serve a one match suspension.
The U's face Gillingham on Saturday, without the services of George Elokobi. That leaves a place alongside Tom Eastman up for grabs and U's boss Tony Humes has said that two players are in contention for it.
"Alex Wynter or Frankie Kent will come in alongside Tom and either of them are more than capable of filling George's boots."
Humes is also without Richard Brindley, who is still recovering from a knee injury, so more cover at the back has been drafted in.
That additional defensive cover comes in the form of Tosin Olufemi, who has impressed in recent U21s matches and could make his first appearance of the season.
There was better news from the treatment room in midfield, with Alex Gilbey recovering from a tight hamstring after missing the Bramall Lane victory.
Also added to the U's squad for the Gills' visit to north Essex is Tom Lapslie, another youngster who has impressed in the past few Development League fixtures.
Squad: Parish, Jones, Vincent-Young, Briggs, Olufemi, Wynter, Eastman, Kent, Lapslie, Edwards, Garvan, Szmodics, Moncur, Gilbey, Ambrose, Harriott, Massey, Sembie-Ferris, Porter, Sordell, Bonne
Squad: Parish, Jones, Vincent-Young, Briggs, Olufemi, Wynter, Eastman, Kent, Lapslie, Edwards, Garvan, Szmodics, Moncur, Gilbey, Ambrose, Harriott, Massey, Sembie-Ferris, Porter, Sordell, Bonne
The U's first team take on Gillingham on Saturday - buy your tickets now at the Advance rate!